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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<script>
    var obj = new Object();//{} 
    obj.species = '动物';
    function Animal(){
    }
    Animal.prototype = obj;
    function Person(){

    }
    Person.prototype = new Animal();
    var su = new Person();
    console.log(su.species,su.__proto__,su.toString())
</script>
</body>
</html>